Lash is the condition in which small spaces lie between the splines of a toothed or geared connection, such as a splined clutch and stator shaft or between planetary gears of an automatic transmission. The gaps in a spline connection are necessary to allow the two structures to be connected during assembly. Similarly, in the case of a sliding or rotating connections, lash exists as the “sliding space” is necessary in order for the connection to function. However, in each case, the spaces or gaps causing the two connected structures to collide with each other when the connection occurs causing an impact that can often be heard when there is a change in inertia or relative motion between the two structures such as when there is a change in torque converter turbine speed.
What is needed then are structures that reduce the space or distance between connection splines or fingers of toothed, geared or similar connections.